Structure for waterproofing a water cistern of a water tower of prefabricated element construction

ABSTRACT

The present invention concerns the waterproofing of cisterns of water towers of prefabricated element construction in such manner that a positively water-tight cistern is obtained. According to the invention the waterproofing consists of an elastic foil placed in the cistern.

United States Patent [191 Janhunen [451 Oct. 7, 1975 STRUCTURE FOR WATERPROOFING A WATER CISTERN OF A WATER TOWER OF PREFABRICATED ELEMENT CONSTRUCTION [76] Inventor: Matti AapeliJanhunen, Kiertotie 2,

Westend, Finland 22 Filed: May 21,1973

21 Appl. No.: 362,078

Related US. Application Data [63] Continuation of Ser. No. 133,846, April 14, 1971,

abandoned.

[30] Foreign Application Priority Data Apr. 15, 1970 Finland 1040/70 [52] US. Cl 52/249; 52/173 [51] Int. Cl. E04B 1/32; E04B 1 1/04 [58] Field of Search 52/247, 249, 224, 225,

[56] References Cited UNITED STATES PATENTS 1,571,484 2/1926 Knight 52/247 2,083,491 6/1937 Chaffee 52/192 2,153,492 4/1939 Workman 52/73 2,864,098 12/1958 Lorimer 52/169 3,073,018 1/1963 Gauthron.... 52/73 3,340,126 9/1967 Knight 52/249 3,383,820 5/1968 Kates 52/475 3,514,909 6/1970 Nevarez.. 52/73 3,600,865 8/1971 Vanich 52/73 FOREIGN PATENTS O'R APPLICATIONS 192,644 2/1923 United Kingdom 220/65 2,032,190 11/1970 France 1,278,724 9/1968 Germany 52/173 Primary Examiner-James L. Ridgill, Jr. Attorney, Agent, or Firm-Waters, Schwartz & Nissen [5 7] ABSTRACT The present invention concerns the waterproofing of cisterns of water towers of prefabricated element construction in such manner that a positively water-tight cistern is obtained. According to the invention the waterproofing consists of an elastic foil placed in the cistern.

7 Claims, 2 Drawing Figures US. Patent Oct. 7,1975

STRUCTURE FOR WATERPROOFING A WATER CISTERN OF A WATER TOWER OF PREFABRllCATED ELEMENT CONSTRUCTION This application is a continuation of Ser. No. 133,846 filed Apr. 14, 1971, and now abandoned.

Heretofore cisterns have mostly been made by pouring them in thick waterproof concrete. A cistern of prefabricated element construction can not be made waterproof so, because when the elements work and move slightly, as they invariably do, the joints begin to leak.

One of the aims of the present invention is to eliminate the drawback presented in the foregoing, and the invention is mainly characterized in that the waterproofing of the cistern consists of an elastic foil placed in the cistern, which foil may consist of plastic, rubber or equivalent. Since a structure of this kind is completely continuous and always absolutely tight, it im poses no requirements on the design of the cistern, other than that it furnishes adequate mechanical support for the waterproofing bag.

A second object of the invention is to provide a cistern which is very easy to clean. According to the invention this is achieved in that several of the said foils are placed one upon the other, the cistern being easily cleaned by removing the uppermost foil, which has become soiled. The foils to be removed consist, for instance, of thin and inexpensive plastic and the number of such foils placed one upon the other may be from 10 to 20.

In the following, one embodiment of the invention is illustrated with the aid of drawings.

FIG. 1 is a longitudinal section through a water tower cistern according to the invention, and in FIG. 2 the section along the line IIII in FIG. 1 has been shown on a larger scale.

In FIG. 1, the column 1 of the water tower is seen and the slab 2 placed on its support. The side wall 3 of the cistern has been assembled from prefabricated concrete elements, and the inner tube 4 and cover 5 of the cistern are also elements. The cistern has been waterproofed by means of a loose foil 6, which has been made of rubber or plastic sheet material, joining such material with water-tight seams to be appropriate in size to fill the interior of the cistern. It is then immaterial with regard to the water-tightness of the cistern even if the elements should move slightly with reference to each other. In the design according to FIG. 2 there is against the cistern wall a sealing foil 6, which is composed of a thicker foil 7 made eg of rubberized fabric and of thin outer foils 8,. which may be 10 to 20 in number and of which the uppermost is removed whenever it has become soiled. It is obvious that the cistern can be provided with normal equipment in all other respects and that between the concrete body of the cistern and the waterproofing bag a thermal lagging consisting of mineral wool or foam plastic may be inserted.

l claim:

1. In a waterproof cistern structure for a water tower adapted to be constructed in situ, including a plurality of wedge-shaped radially extending prefabricated concrete elements forming a bottom wall surface of said cistern structure; a central column for said water tower supporting said bottom wall surface; a plurality of contiguous upstanding concrete elements being supported on said radially extending concrete elements proximate the radially outer edges thereof so as to form the peripheral wall of said cistern structure; the improvement comprising: at least one single-piece liquid-tight elastic foil being positioned in said cistern structure, said elastic foil being freely suspended from the upper ends of said central column and said upstanding concrete elements so as to extend in unattached superposition along the bottom wall, upstanding wall surfaces of said concrete elements and central column for substantially the entire external surfaces of said foil whereby said foil is maintained in surface contact with said cistern structure through the force of water pressure therein.

2. A structure as claimed in claim 1, said elastic foil being formed of a rubberized fabric material.

3. A structure as claimed in claim 1, said elastic foil being formed of rubber.

4. A structure as claimed in claim 1, said elastic foil being formed of a plasticized material.

5. A structure as claimed in claim 1, said elastic foil being formed of a plastic material.

6. A structure as claimed in claim 1, comprising a plurality of elastic foils being disposed in said cistern in superimposed relationship, at least the uppermost layers being readily peelable from the lower elastic foil layers.

7. A structure as claimed in claim 6, at least the lowermost layer of said elastic foils contacting said cistern elements being of a thickness greater than the thicknesses of the individual foil layers superimposed 

1. In a waterproof cistern stRucture for a water tower adapted to be constructed in situ, including a plurality of wedge-shaped radially extending prefabricated concrete elements forming a bottom wall surface of said cistern structure; a central column for said water tower supporting said bottom wall surface; a plurality of contiguous upstanding concrete elements being supported on said radially extending concrete elements proximate the radially outer edges thereof so as to form the peripheral wall of said cistern structure; the improvement comprising: at least one single-piece liquid-tight elastic foil being positioned in said cistern structure, said elastic foil being freely suspended from the upper ends of said central column and said upstanding concrete elements so as to extend in unattached superposition along the bottom wall, upstanding wall surfaces of said concrete elements and central column for substantially the entire external surfaces of said foil whereby said foil is maintained in surface contact with said cistern structure through the force of water pressure therein.
 2. A structure as claimed in claim 1, said elastic foil being formed of a rubberized fabric material.
 3. A structure as claimed in claim 1, said elastic foil being formed of rubber.
 4. A structure as claimed in claim 1, said elastic foil being formed of a plasticized material.
 5. A structure as claimed in claim 1, said elastic foil being formed of a plastic material.
 6. A structure as claimed in claim 1, comprising a plurality of elastic foils being disposed in said cistern in superimposed relationship, at least the uppermost layers being readily peelable from the lower elastic foil layers.
 7. A structure as claimed in claim 6, at least the lowermost layer of said elastic foils contacting said cistern elements being of a thickness greater than the thicknesses of the individual foil layers superimposed thereon. 